Forensic Psychology Lab

Expert Evidence

When courts are required to grapple with complex issues beyond their expertise, there are legal provisions to allow for the introduction of expert evidence to help the trier of fact (the judge or jury) to understand these complex issues. Australian courts have used such experts to help them interpret a variety of evidence including eyewitness reports, and CCTV images through forensic facial comparison and/or body mapping. However, there is little evidence to suggest that the introduction of expert evidence help jurors reach more accurate decisions. Moreover, research has shown that experts are extremely persuasive to jurors even when their conclusions are erroneous. As a result, expert evidence can be very persuasive but potentially misleading and hence dangerous to an innocent defendant.

The influence that expert evidence has on jurors is extremely important. One of our research projects in in this area is investigating whether the conventional legal safeguards in place in NSW courts are sufficient to expose weaknesses or inaccuracies in expert testimony. Preliminary results indicate that these safeguards are inadequate.